subprocess模块(了解)

一、subprocess模块

subprocess模块允许你去创建一个新的进程让其执行另外的程序，并与它进行通信，获取标准的输入、标准输出、标准错误以及返回码等。更多查看官网：https://docs.python.org/2/library/subprocess.html?highlight=subprocess#frequently-used-arguments

import subprocess
import subprocess
'''
sh-3.2# ls /Users/nick/Desktop |grep txt$
mysql.txt
tt.txt
事物.txt
'''

res1 = subprocess.Popen('ls /Users/jieli/Desktop',
                        shell=True,
                        stdout=subprocess.PIPE)
res = subprocess.Popen('grep txt$',
                       shell=True,
                       stdin=res1.stdout,
                       stdout=subprocess.PIPE)

print(res.stdout.read().decode('utf-8'))

# 等同于上面,但是上面的优势在于,一个数据流可以和另外一个数据流交互,可以通过爬虫得到结果然后交给grep
res1 = subprocess.Popen('ls /Users/jieli/Desktop |grep txt$',
                        shell=True,
                        stdout=subprocess.PIPE)
print(res1.stdout.read().decode('utf-8'))

# windows下:
# dir | findstr 'test*'
# dir | findstr 'txt$'
res1 = subprocess.Popen(r'dirC:\Users\Administrator\PycharmProjects\test\函数备课',
                        shell=True,
                        stdout=subprocess.PIPE)
res = subprocess.Popen('findstr test*',
                       shell=True,
                       stdin=res1.stdout,
                       stdout=subprocess.PIPE)

# subprocess使用当前系统默认编码，得到结果为bytes类型，在windows下需要用gbk解码
print(res.stdout.read().decode('gbk'))